Photographic emulsion



ted-July 20, 943

Delaware present invention relates to photographic and more particularly to new silver de emulsionsfor color forming development. is known tonse aliphatic or aromatic amides hydroxy acids capable of coupling as color rs for the blue in the production of color tographic images. Moreover, it has already proposed to 'select suitable amines for dating the acid group in order to influence tint of the dyestufl'. It is, therefore, possible reduce blue-green colors having a strongly tint chiefly desired for the negative process urely blue colors advantageous for the posiprocess, by means'of suitable amines. Hownot only 'is-the'tint of importance for the lay of the color images but the gradation i also is of significance. Thus it is, for ince, desirable for the negative process that possible be available. 4

present invention is based on the observa-. that a blue-green dyestufl having a high eability to green rays and a color image a very flat gradation are obtained on the development of silver halide emulsions 11 contain as the color former a condensation uct from an aromatic-hydroxy acid and an tic amine which is substituted in 'or pg a radicle producing fastness to difiusion hich is further substituted by an acid group r p-position to the latter amino group. e aromatic hydroxy acids capable of coufor instance, include the following comdsz a hydro'xynaphthoic acid, l-hydroxythalene-Z-sulfonic acid, l-hydroxynaphtha- 6 sulfonic acid, 1.2.3.4-xylenolcarboxylic i5.6-dimethoxyphenol-2-carboxylic acid, 1- xycarbazole-2-carboxylic acid, hydroxycin- H c acid, and 2.6-phenoldicarboxylic acid. The hydroxy acids are condensed with oorpines one amino group of which contains a ee, described in the following patents and cations:

[8. Patents 2,186,852, 2,186,719, 2,186,734, 88 51, 2,186,733, 2,186,732, 2,186,847 dated Jan- 9, 1940, U. S. Patents 2,179,238, 2,179,244, 78, 12 dated November 7, 1939, U. S. Patents 2,280,722 dated April 21, 1942, and 2,303,928 December 1, 1942, French Patents 344,648,.

844,637, and U. S. Patents 2,280,722, ,575, 2,303,928 and 2,307,399 and U. S. appli- Ser. No. 284,258 filed July 13, 1939, 333,814 May'l, 1940, 335,144 filed May-14, 1940,

UNITED, i STATES PATEN f 2.82am

Alfred Friihlich and Wilhelm Schneider, Des-an, Germany',-"aalignors to General Aniline & Film- 1 Corporation, New York, N. Y., a corporation of '1" owner:

No Drawing. Application July 15, 1941, Serial No. 402,546."!11 Germany July 16, 1940 4 Claims. (Cl. 95-8) 341,180 filed June 18, 1940, and 362,592 flied October 24, 1940. I

Amines suitable for preparing color formers of I the present invention are, for instance, the following compounds: l-amino-a-methyloctadecylaminobenzene-B-sulfonic acid, 1-amino-4-do- 'decylaminobenzene-a-carboxylic acid, l-amino- 4 abietinylaminobenrene 3 sulfonic acid, 1- amino-4-perhydrodiphenylaminobenzene -3- carboxylic acid, 1-amino-2-oleylaminobenzene-5- sulfonic acid, l-amino-2-abietinylaminobenzene- 5-carboxylic acid, 1-amino-2-methyloctadecylformers yielding a dyestufi image as 'fiat tlon to the amino group by an amino group an t e producing fastness to difiusion as, for in- I aminobenzene-3-.-carboxylic acid, or l-amino-Z- dodecylaminobenzene-3-sulionic acid. These amines may be produced by boiling the coner sponding nitrocl'ilorosulfonic' acids in the form of capable of combining with acids, the hydrom acid being used in a reactive form. for instance.

as an ester or acid chloride.

- Color formers in accordance with the present invention are, for instance, the following condensation products: 1 hydroxy 2 naphthoylamino- 4'-methyloctadecylaminobenzene-3'-sultonic acid:

1.2.3.4 iylenolcarboylamino 4' perhydrodiphenylaminobenzene-ii'-carboxylic acid:

1'- hydroxy 2 naphthoylamino -2'-methyloctadecylaminobenzene-fi-sulfonic acid:

BOIH

CONH solubility of the sodium salts is increased. The color formers are added in the form of the sodium salts to the silver halide emulsions in any stage of the production thereof. On development with a color forming developer such as pdimethylaminoaniline one obtains blue-green dyestufi images having a very flat gradation.

The silver halide gelatin emulsions prepared by the present color formers may be cast to form single layers or worked up into a multi-layer material for color photography by superimposing on each other, several silver halide emulsion layers containing diiferent dyestuff formers on one or both sides of the support. If necessary, the multi-layer material may be provided with filter layers, intermediate layers, and anti-halation layers. The color images may be produced by a simple or a reversal development, i. e. as a negative or a positive, respectively.

We claim:

1. A color photographic silver-halide emulsion containing as the color former the compound of the following structural formula wherein R. is a hydroxy aryl radicle and A is an aryl radicle which is substituted by an amino group carrying a radicle capable of rendering said color former fast to diffusion, said amino group being in a position selected from the class consisting of the oand p-positions relative to the amido linkage and by an acid group in a position selected from the class consisting of the 0- and p-positions relative tothe amino group carrying said radicle.

2. A color photographic silver-halide emulsion containing as the color former a compound corresponding with the following formulai CH: CONH N Cunt! Oil! 3. A color photographic silver-halide emulsion containing as the color former a compound corresponding with the following formula:

4. A color photographic silver-halide emulsion containing as the color former a compound corresponding with the following formula:

0H son; 4

CONH

' CHa-N-CnHrl ALFRED momma. wmrmmw scmmmm 

